1. Field of the Invention
The invention relates generally to immunotherapy and, more specifically, to multivalent polypeptides directed to CD3 and CD11b cell surface markers, which markers are present on a subpopulation of immunosuppressing T cells, for therapeutic and diagnostic and prognostic use in cancer and infectious disorders.
2. Background Information
Patients with Chronic Lymphocytic Leukemia (CLL), usually a “B” cell cancer, commonly have abnormally large populations of certain kinds of non-cancerous “T” cells in the blood which have many CD11b molecules on their surface. Similarly, patients with progressive debilitating HIV-1 infections also have abnormally large populations of T cells with CD11b molecules on their surface, which normally comprise only a small percentage of the T cells in the blood of healthy people.
Evidence indicates that these T cells with CD11b on their surface (i.e., “CD11b+”) can interfere with or suppress the body's immune responses, and thus may have deleterious effects on one's ability to fight off cancer or HIV-1 infection. It appears that many types of human cancer and HIV-1 infection may elicit increased production of these CD11b+ T cells as a way of evading the immune response of the host.